In the Korean Peninsula, the current distribution of the warm-temperate and subtropical vegetation (including many homosporous ferns) is limited to southern coastal areas. Paleoecological data suggest that during the Last Glacial Maximum this vegetation retreated to glacial refugia putatively located in southern Japan and/or southern China, followed by a post-glacial recolonization. Two broad scenarios of post-glacial recolonization could be hypothesized: extant Korean populations are derived from multiple source populations (i.e., from multiple refugia); alternatively, they originate from a single refugium. To test which of these scenarios is more likely, we surveyed patterns of genetic diversity in eight (n  =  307) populations of Cyrtomium falcatum from southern Korea. We found extremely low levels of allozyme variation within populations coupled with high among-population differentiation. These data best support the second hypothesis, and indicate that the current genetic diversity may be a consequence of post-glacial long-distance dispersal events and subsequent founder effects. In addition, restricted gene flow among the discontinuous populations of C. falcatum in southern Korea has likely contributed to the high degree of among-population genetic differentiation. From a conservation perspective, several populations should be targeted for both in situ and ex situ conservation, as C. falcatum exhibits a high degree of divergence among populations.

Scanning electron microscope (SEM) studies of stem and strobilus longisections of Huperzia, Lycopodium, and Phylloglossum were undertaken to explore ultrastructure of pit membranes in tracheids. The membranes do not characteristically have pores and may often lack evidence of cellulosic fibrils. Some pit membranes in Lycopodium did show cellulosic fibrils. Porose membranes were seen in some tracheids, an appearance probably related to scraping away of layers in pit membranes by the sectioning process, or in other cases, artifact formation. Metaxylem tracheids have wide borders on pits. Truly “reticulate” metaxylem tracheids are few. Protoxylem tracheids have helices with borders in Huperzia and Lycopodium, but in Phylloglossum protoxylem annuli and helices are non-bordered. Phylloglossum, which appears nested in Huperzia, lacks metaxylem and has numerous other adaptations to the distinctive ephemeral vernal bogs of Australia and New Zealand, similar to those in Droseraceae and Orchidaceae.

We describe and illustrate a new firmoss, Phlegmariurus changii (Huperziaceae), which is endemic to eastern Taiwan. This new species is most similar to Phlegmariurus carinatus (Desv. ex Poiret) Ching; however, it differs by leaves that are flat abaxially. In addition, the sporophylls and trophophylls are conspicuously dimorphic for Phlegmariurus changii, but essentially monomorphic in Phlegmariurus carinatus. The ecology, conservation status, and morphology of P. changii is compared to that of species in three other sections (Sect. Phlegmariurus, L. B. Zhang, Sect. Huperzioides H. S. Kung et L. B. Zhang, and Sect. Carinaturus (Herter) H. S. Kung et L. B. Zhang) of Phlegmariurus in East Asia.

The typification of the binomium Marsilea quadrifolia L. (Marsileaceae) is discussed. To fix the application of the species name an iconography by de Jussieu is designated as the lectotype.